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Group Title: Computer series Florida Cooperative Extension Service
Title: Greenhouse cooling
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00095232/00002
 Material Information
Title: Greenhouse cooling cost analysis software for pad and fan cooling system
Series Title: Computer series Florida Cooperative Extension Service
Physical Description: 1 computer disk : ; 5 1/4 in. +
Language: zxx
Creator: Roy, B. L.
Jones, R. H.
Zazueta, Fedro S.
Polak, J. T.
Publisher: Florida Cooperative Extension Service/ Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 1989
Copyright Date: 1989
Edition: Version 1.0.
 Subjects
Subject: Greenhouses -- Heating and ventilation   ( lcsh )
 Notes
Summary: This program was developed to evaluate the costs of greenhouse pad and fan evaporative cooling systems. Using the input information, the program calculates an annual cost for the operation of the cooling system.
Statement of Responsibility: B.L. Roy .. et al..
System Details: System requirements: IBM PC or compatible with MS-DOS; 1 floppy disk drive. Recommended: printer.
General Note: Description based on: documentation dated June 1989.
General Note: Florida Cooperative Extension Service, computer series circular 838
 Record Information
Bibliographic ID: UF00095232
Volume ID: VID00002
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 20697936

Table of Contents
    Front Cover
        Page i
    Disclaimer
        Page ii
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
    Back Cover
        Page 13
        Page 14
Full Text
(01
fC 5c
P Disk(s) under separate cover
June 1989


Circular 838


GREENHOUSE COOLING


Cost Analysis Software for


Pad and Fan Cooling


Systems


B. L. Roy, R H. Jones, F. S. Zazueta, and J. T. Polak


Florida Cooperative Extension Service/Institute of Food and Agricultural Sciences
University of Florida/John T. Woeste, Dean

101
F636c
838 i
codebk









DISCLAIMER


The Board of Regents of the State of Florida, the State of Florida, the University of Florida,
the Institute of Food and Agricultural Sciences, and the Cooperative Extension Service,
hereinafter collectively referred to as "UF-IFAS", will not be liable under any circumstances for
direct or indirect damages incurred by any individual or entity due to this software or use
thereof, including damages resulting from loss of data, lost profits, loss of use, interruption of
business, indirect, special, incidental or consequential damages, even if advised of the possibility
of such damage. This limitation of liability will apply regardless of the form of action, whether
in contract or tort, including negligence.

UF-IFAS does not provide warranties of any kind, express or implied, including but not
limited to any warranty of merchantability or fitness for a particular purpose or use, or
warranty against copyright or patent infringement.

The entire risk as to the quality and performance of the program is with you. Should the
program prove defective, you assume the entire cost of all necessary servicing, repair, or
correction.

The mention of a tradename is solely for illustrative purposes. UF-IFAS does not hereby
endorse any tradename, warrant that a tradename is registered, or approve a tradename to the
exclusion of other tradenames. UF-IFAS does not give, nor does it imply, permission or license
for the use of any tradename.

IF THE USER DOES NOT AGREE WITH THE TERMS OF THIS LIMITATION OF
LIABILITY, USER SHOULD CEASE USING THIS SOFTWARE IMMEDIATELY AND
RETURN IT TO UF-IFAS. OTHERWISE, USER AGREES BY THE USE OF THIS
SOFTWARE THAT USER IS IN AGREEMENT WITH THE TERMS OF THIS LIMITATION
OF LIABILITY.













GREENHOUSE COOLING


Cost Analysis Software for
Pad and Fan Cooling Systems


B. L. Roy, P. H. Jones, F. S. Zazueta, and J. T. Polak*


INTRODUCTION

Nearly every location in Florida
experiences periods of intense heat causing
greenhouse temperatures to become 10 to 200
F higher than outdoors. Such conditions are
too hot for satisfactory plant growth. Using
the principles of psychometrics, an effective
and economical method of evaporative
cooling can be designed to maintain
greenhouse temperatures as much as 150 F
below the outdoor, dry bulb temperature. In
effect, this would produce greenhouse
temperatures up to 350 F lower than in a
conventional, uncooled greenhouse.

Pad and fan evaporative cooling systems
offer growers an economical opportunity to
prevent excessively high greenhouse
temperatures, maintain more uniform
conditions throughout the house, obtain
better temperature and humidity control,
and produce an improved growing climate.
As described by the Acme Engineering and
Manufacturing Corporation, this improved
environment offers the following benefits:

1. Cools greenhouses 20 to 300 F during hot
months.

2. Produces high quality crops year-round.

3. Permits growing crops not previously
successful.


4. Permits higher light intensities for more
lush, vigorous growth.

5. Reduces watering requirements.

6. Keeps plants on schedule.

7. Produces clean, filtered, moist air--ideal
for plant growth.

8. Provides better insect control.

9. Provides more comfortable working
conditions and improved employee
efficiency.

10. Eliminates stagnant air and produces a
better leaf surface microclimate for
improved plant growth.

11. Simplifies greenhouse design and reduces
basic construction costs.

This program was developed to evaluate
the costs of greenhouse pad and fan
evaporative cooling systems. The program
requires the input information to
characterize each particular greenhouse,
including its pad system, fan system,
machinery and power requirements as well
as other features. Using the input
information, the program calculates an
annual cost for the operation of the cooling
system.


*Graduate Assistant, Assistant and Associate Professor, and Graduate Assistant respectively,
Agricultural Engineering Department, Institute of Food and Agricultural Sciences, University of
Florida, Gainesville, FL 32611.










INPUT DATA

1. Number of fans--the number of cooling
fans used in the greenhouse.

2. Size of fans--the diameter of the fan
blade [inches].

3". Cost per fan--the dollar cost per fan,
excluding the motor [US $].

4. Expected fan life--expected useful life
before replacement is required [years].

5. Interest rate--at the time the equipment
was purchased, the rate of interest you
would have had to pay to buy the
equipment [%].

6. Number of motors--the number of
motors needed to run the fan system.

7. Motor power ratings--the average
horsepower rating of the fan motors [hp].

8'. Cost per motor--the dollar cost per fan
motor, excluding the fan [US $].

9. Expected motor life--expected useful
life before replacement is required
[years].

10. Pad thickness--the depth of the pad wall
[inches].

11. Pad age--current age of the pad [years].

12. Pad cost/square ft.--the dollar cost per
pad per square foot [US $/ft2].

13. Pad area--the effective area of the pad
[ft2].

14. Installation costs--the dollar cost of
installing the pad, including labor,
excluding parts [US $/ft2].

15. Expected pad life--expected useful life
before replacement is required [years].


16. Watering system hardware--the dollar
cost of the water handling system;
valves, hoses, sprinkler heads, pumps,
etc. [US $].

17. Water pump rating--the horsepower
rating of the water pump [hp].

18. Pad support hardware--the dollar cost of
the equipment needed to support the
pads [US $].

19. Expected watering system and pad
support hardware life--expected useful
life before replacement is required
[years].

20. Winter--the amount of time the cooling
system operates during the winter
months [hr/day].

21. Spring--the amount of time the cooling
system operates during the spring
months [hr/day].

22. Summer--the amount of time the
cooling system operates during the
summer months [hr/day].

23. Fall--the amount of time the cooling
system operates during the fall months
[hr/day].

24. Electrical power costs--the dollar cost
for electricity for the greenhouse [US $/
kw-hr].

25. Annual fan system maintenance--hours
per year spent maintaining and repairing
the fan system [hr/yr].

26. Annual pad system maintenance--hours
per year spent maintaining and repairing
the pad system [hr/yr].

27. Labor costs--cost for skilled labor for
greenhouse operations [US $/hr].


alf fans and motors are purchased as a
single unit, the costs should be divided
proportionately when entering data.










SAMPLE RUNb

1. Insert the "Greenhouse Cooling" diskette
in drive A, and turn the computer on.

2. Type GREEN . If the banner
in Screen 1 is displayed on the monitor,
the program has been successfully
loaded.

3. After a short period of time, the monitor
will display the Disclaimer, as shown on
Screen 2.

4. The General Overview will appear after
a few seconds as shown in Screen 3. At
this point, press "B" to begin the program
or press "Q" to exit the program.

5. If you pressed "B", Screen 4 will appear
on the monitor. Enter the data for the
dimensions of the greenhouse and press
the "End" key when finished.

6. At this point, either continue the
program by pressing "C" or start the
screen over by pressing "P".

7. If you pressed "C", Screen 5 will appear
on the monitor. You can now enter the
data for the fan specifications in the
greenhouse and press the "End" key
when finished.

8. At this point, either continue the
program by pressing "C", or return to the
previous screen by pressing "P".

9. Repeat steps 8 and 9 for Screens 6, 7, 8,
9, 10 and 11 to input all of the needed
parameters to calculate the cooling costs
of the greenhouse.

10. The last three screens--12, 13 and 14--
represent a summary of the greenhouse
expenses. When you have finished
reviewing the results, press "C" to
continue to the next screen or "P" to
return to the previous screen.


11. When you have reached screen 14, you
may end the program by pressing "Q",
start over by pressing "C", or return to
the previous screen by pressing "P".

PROGRAM NOTES

1. If the following message appears on the
screen "Value out of range, accept?"
check the value entered to see if it is
correct. If it is correct, press "Y"; if it is
incorrect, press "N" and enter the correct
value.

2. The program will prompt you for the
interest rate for equipment needed in the
greenhouse cooling system. Enter the
interest rate at the time you bought the
equipment. You must enter a value for
the interest rate even if you paid case
for the equipment.

TECHNICAL NOTES

The input data requested in this program
are used to specify physical dimensions and
cooling equipment for a particular pad and
fan cooling system. The following equations
show how the calculations are performed in
the program.

greenhouse floor area = length of the
greenhouse x width of the greenhouse

volume = greenhouse floor area x average
height

average height = ground level to the
midheight of the roof above the wall


i (1 + i)n
capital recovery factor =
(I + i)f -1


where i = interest rate (decimal)
n = number of years


bNOTE: Screens are shown in the
APPENDIX.











total fan cost = number of fans x cost per
fan

total motor cost = number of motors x cost
per motor

total pad cost = pad area x pad cost + pad
area x installation cost

total hardware cost = watering system cost +
pad support cost + hardware cost

total power requirement = number of motors
x motor power rating + water pump
rating

annual fan cost = total fan cost x fan capital
recovery factor

annual motor cost = total motor cost x motor
capital recovery factor

annual pad cost = total pad cost x pad capital
recovery factor

annual hardware cost = total hardware cost
x hardware capital recovery factor

annual power requirements = total power
requirements x annual operation time
x 0.7457

annual power cost = annual power
requirements x power cost

annual maintenance time = total fan
maintenance + annual pad maintenance

annual maintenance cost = annual
maintenance time x labor cost

total annual fan system cost = annual fan +
annual motor costs


total annual pad system cost = annual pad +
annual hardware costs

total annual fixed cost = total annual fan +
pad system costs

total annual variable cost = annual power +
annual maintenance costs

REFERENCES

Barmby, B., R. Bucklin, and P. Jones,
Cooling System Analysis Workshop,
Florida Cooperative Extension Service
(1986).

The Greenhouse Climate Control Handbook:
Principles and Design Procedures, Acme
Engineering and Manufacturing Corp.,
Muskogee, Oklahoma (1977).

ACKNOWLEDGMENTS

The authors would like to express their
appreciation to Laurie E. Neff for her
editorial assistance.

TECHNICAL SUPPORT

For assistance with this program, contact
the IFAS Software Support Office by phone
at (904) 392-7853 or mail to: IFAS Software
Support Office, Building 120, Room 203,
Gainesville, FL 32611.

This program as well as other programs
developed by IFAS are available from the
IFAS Software Support Office. To place an
order or request a catalog, contact: IFAS
Software Support Office, Bldg. 120, Room
203, Gainesville, FL 32611 or telephone
(904) 392-7853.




























Screen 1


Screen 2


Institute of Food and Agricultural Sciences

Agricultural Engineering Department



Pad and Fan Cooling Systems


Version 1.0


Copyright 1988
University of Florida


The Institute of Food and Agricultural Sciences,
The University of Florida and the authors of this
software make no explicit or implicit warranties
on the use of this software. The responsibilities
for all consequences of using this software remain
solely with the user.










Worksheet for Pad and Fan Cooling Systems


General Overview:

The purpose of this program is to analyze the
relative economic efficiency of particular pad
and fan evaporative cooling systems. The system
that you chose to evaluate should be representa-
tive of a single greenhouse or greenhouse range.
It should not be a composite of differently
equipped or operated houses.


Press "B" to begin program


Press "Q" to exit program


Screen 3


Greenhouse


1. Length

2. Width

3. Height (average)


Type "C" to continue program


Type "P" to go to the previous screen


Screen 4


58.0 ft.

26.0 ft.

8.3 ft.





























Screen 5


Motor System


Number of motors

Motor power ratings

Cost per motor

Expected motor life

Interest rate


Type "C" to continue program


3.00

2.00 hp

310.00 $/motor

8.00 years

12.00 %


Type "P" to go to the previous screen


Screen 6





























Screen 7


Hardware

1. Watering system hardware

2. Water pump rating

3. Pad support hardware

4. Expected hardware life

5. Interest rate


Type "C" to continue program


1,512.00 $

16.00 hp

388.00 $

7.00 years

10.00 %


Type "P" to go to the previous screen


Screen 8


Pad System

1. Pad thickness 4.00 inches

2. Pad age 6.00 years

3. Pad costs/sq. ft. 5.13 $/ft.

4. Pad area 60.00 sq. ft.

5. Installation costs 6.23 $/sq. ft.

6. Expected pad life 6.00 years

7. Interest rate 14.00 %

Type "C" to continue program Type "P" to go to the previous screen









Well System

1. Well diameter

2. Portion used by

3. Well costs

4. Well pump ratil

6. Expected well li

7. Interest rate


Type "C" to continue program


10.00 inches

22.00 %

4,000.00 $

2.00 hp

20.00 years

12.00 %


Type "P" to go to the previous screen


Screen 9


Annual Operating Time


1. Winter

2. Spring

3. Summer

4. Fall





Type "C" to continue program


1.00 hours/day

4.00 hours/day

8.00 hours/day

6.00 hours/day





Type "P" to go to the previous screen


Screen 10









Annual Power Costs

1. Electrical power costs


Annual Maintenance Time

1. Annual fan system maintenance

2. Annual pad system maintenance

3. Labor costs


Type "C" to continue program


0.05000 $/kw.-hr.



40.00 hours/year

40.00 hours/year

8.00 $/hour


Type "P" to go to the previous screen


Screen 11


Screen 12


Summary of Greenhouse Costs--page 1 of 3

1. Annual fan cost 186.21 $/year

2. Annual motor cost 187.21 $/year

3. Annual pad cost 175.28 $/year

4. Annual hardware cost 390.27 $/year

5. Annual power cost 1,430.71 $/year

6. Annual maintenance 640.00 $/year



Then press "C" to continue or "P" for the previous screen.








Summary of Greenhouse Costs--page 2 of 3

Annual fixed cooling system cost

Total annual fan system cost
Total annual pad system cost

Total annual fixed cost
Fixed cost per unit area

Annual variable cooling system cost

Total annual variable (operation) cost
Variable cost per unit area


373.42 $/year
683.36 $/year

1,056.79 $/year
0.70 $/year/sq. ft.



2,070.71 $/year
1.37 $/year/sq. ft.


Then press "C" to continue or "P" for the previous screen.


Screen 13


Summary of Greenhouse Costs--page 3 of 3


Total annual greenhouse cost

Total annual greenhouse cost per unit area


3,127.50 $/year

2.07 $/year/sq. ft.


THIS IS THE END OF THE PROGRAM



Then "C" to start over, "P" for the previous screen, or "Q" to end.


Screen 14























































































COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES. G.L.
Zachariah, director, in cooperation with the United States Department of Agriculture, publishes this information to further the purpose of the
May 8 and June 30, 1914 Acts of Congress; and is authorized to provide research, educational information and other services only to
individuals and institutions that function without regard to race, color, sex, age, handicap or national origin. Information on copies for purchase
is available from C.M. Hinton, Publications Distribution Center, IFAS Building 664. University of Florida. Gainesville, Florida 32611. Before
publicizing this publication, editors should contact this address to determine availability.




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